Make n the subject of the formula: m = 5n - 21

The answer is: n = (m + 21)/5 How did we get this? Right now, the equation is written in the form where m is the subject. We want to rearrange this so that n is the subject of the formula. The formula should look like this: n = ___________________ So how do we do this? Step 1) We plus 21 to both sides of the equation. So the equation should now read m + 21 = 5n Step 2) Now we know that 5n = m + 21. We want to know what 1n equals so we have to divide both sides by 5. The equation is now 1n = (m + 21)/5 which is your answer. Does this make sense? If so, try the next questions! * Make R the subject of the formula:       S = 3r + 15 * Make y the subject of the formula:       X = 1/2 y + 20 

JC

Related Maths GCSE answers

All answers ▸

How do you solve these simultaneous equations? 4x + 5y = 8; 2x + 3y = 5


Rationalise the denominator of the following fraction: 1/(√2 + 1)


How do you solve linear inequalities such as: 5x – 2 > 3x + 11


Make 'a' the subject of the formula: p = (3a + 5) / (4 - a)